CONTINUOUS TAMOXIFEN TREATMENT IN ASYMPTOMATIC, POSTMENOPAUSAL BREAST-CANCER PATIENTS DOES NOT CAUSE AGGRAVATION OF ENDOMETRIAL PATHOLOGIES

Adjuvant tamoxifen therapy for breast cancer patients has been found t o be associated with various endometrial pathologic conditions, includ ing endometrial cancer. This preliminary case control study evaluated whether prolonged and continuous exposure to tamoxifen in the menopaus e may aggravate existing endometrial pathologies. Two vaginal ultrasou nd evaluations of endometrial thickness and histologic findings of two endometrial biopsies, performed 18 months apart, were evaluated for 2 5 asymptomatic, postmenopausal breast cancer patients who were continu ously treated with tamoxifen. In the first endometrial biopsy, 4 patie nts (16.0%) were found to have endometrial pathologies: 2 patients had proliferative endometrium, 1 had hyperplastic endometrium, and 1 had an endometrial polyp. In the second endometrial biopsy, none of these patients showed any endometrial pathologies. Another patient (4.0%) wi th no endometrial pathology in the first visit had endometrial hyperpl asia in the second visit. None of the patients developed endometrial c ancer, and generally there was no increase in ultrasonographically-mea sured endometrial widths. The results of this preliminary study may su ggest that there is no increased risk of development of endometrial pa thologies during an additional 18 months of continuous tamoxifen thera py nor is there aggravation of already existing endometrial pathologie s. (C) 1994 Academic Press, Inc.